Prof. Doutor Mário Marques da Silva
Prof. Doutor João Guerreiro
Outline
▪ Evolução das Comunicações Celulares
▪ As Comunicações 5G, suas diferenças
▪ Técnicas de Transmissão de Suporte ao 5G
▪ MIMO e Massive MIMO
▪ Técnicas de Transmissão por Blocos (Prof.
João Guerreiro)
Outline
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▪ Evolução das Comunicações Celulares
▪ As Comunicações 5G, suas diferenças
▪ Técnicas de Transmissão de Suporte ao 5G
▪ MIMO e Massive MIMO
▪ Técnicas de Transmissão por Blocos
Evolução das Comunicações Celulares
Suporte a Serviços Disponibilizados
• 1G (FDMA) – Analógica (voz)
• 2G (TDMA) – GSM – Digital, Introdução dos Dados e do Roaming
• 3G (WCDMA) – UMTS – Acesso à Internet
• 4G (OFDM) – VTC (estático, difícil equalização)
• 5G (OFDM) – VTC (on the move), Condução Autónoma, Comunicações
ponto-a-ponto (IoT), Realidade Virtual, Inteligência Artificial, etc.
• Normalizado em normas 3GPP da ETSI, tendo sido adotado pela ITU-T
• Liderança das Normas Celulares Europeias
Introduction
• xxxxxx
O Novo Paradigma das Comunicações 5G e as Técnicas de Transmissão de Suporte, Dezembro 2017
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Base Station Cooperation
Mitigates Path Loss, Shadowing, Inter-cell Interference
Increases SNR
Multi-Hop Relay
Mitigates Path Loss, Shadowing, Inter-cell Interference
Increases SNR
BS RS RS RS RS RS RS UE 1 UE 2Outline
▪ Evolução das Comunicações Celulares
▪ As Comunicações 5G, suas diferenças
▪ Técnicas de Transmissão de Suporte ao 5G
▪ MIMO e Massive MIMO
As Comunicações 5G, suas diferenças
• 5G systems (2020) are aimed to achieve:
• Higher throughputs (1 to 10 Gbps)
• Lower Latency (0,5-1 ms latency)
• Higher Capacity
• Better Spectral Efficiency
• 3GPP Release 15 (from ETSI)
• Covers: 1-Radio Access Network; 2-Services and Systems Aspects; 3-Core Network and Terminals
• ITU-T will standardize 5G as
IMT-2020
• Data, data, data…
(High Speed).
• 5G will support:
VTC on the move, real-time communications, augmented reality, support
of self-driving cars, machine-to-machine communications, etc.
• Both infrastructure centralized architecture and
device-to-device communication (to
support IoT, MANET, and Security Application)
• Massive MIMO schemes involving several tens or even hundreds of antenna elements are
expected to be central technologies for 5G systems
New Paradigm of 5G
• Support of new and emerging services
• Increase of data rates (10 Gb/s) and lower delays
• Increase of offer tends to originate an increase of demand => new
services will come
5G main Requirements:
• Transmission Rates: 10 Gbps nomadic and 1 Gbps on the move in
downlink (halved in the uplink).
• Latency: 0,5 ms for tactile interaction.
• Capacity: targets can be as high as 15 Tbps/km2 with 250 000 users/km2
for indoor hotspots such as office environments.
•Spectral Efficiency
•Downlink 30bit/s/Hz -
services require more in the downlink
•Uplink 15bit/s/Hz -
uplink is the bottleneck, due to lower Tx Power, and lower
number of Tx antenas, …
HOW TO ACHIEVE 5G?
• Massive MIMO
(instead of conventional MIMO)
• Base Station Cooperation
• Multi-hop Relay
• All-over IP
• Adaptive Modulation and Coding
• Multi-Resolution Techniques
• OFDM and other block Transmission Techniques
• Carrier Agreggation
• Etc.
•Hundreds or Thousands
of Tx and Rx Antennas
•Complexity grows exponentially =>
Signal
Processing
•mm-Wave facilitates m-MIMO
, as distance
between antennas is reduced.
Massive MIMO
• mm-Wave communications
(30-300GHz - EHF) are expected to be a
crucial part of 5G systems due to their
increased channel
coherence bandwidth
, as compared to centimeter Wave. These
systems use carrier frequencies of 30 - 70 GHz, where we have
large unoccupied bandwidth.
• Ex: IEEE802.11ad uses 2.16 GHz of BW in 60 GHz band (ISM band), supporting up to 7
Gbps.
• Moreover, the distance between antennas is reduced, facilitating a
higher number of antennas elements (Massive MIMO)
• However,
mm-Wave suffers from high path loss and rain and
oxygen absorption.
Outline
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▪ Evolução das Comunicações Celulares
▪ As Comunicações 5G, suas diferenças
▪ Técnicas de Transmissão de Suporte ao 5G
▪ MIMO e Massive MIMO
▪ Técnicas de Transmissão por Blocos
Multipath Interference
Intersymbol Interference
• Higher Signal Bandwidth corresponds to higher
Intersymbol Interference
Outline
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